Healthy younger and older adults control foot placement to avoid small obstacles during gait primarily by modulating step width
Open Access
- 1 January 2012
- journal article
- Published by Springer Science and Business Media LLC in Journal of NeuroEngineering and Rehabilitation
- Vol. 9 (1), 69
- https://doi.org/10.1186/1743-0003-9-69
Abstract
Falls are a significant problem in the older population. Most falls occur during gait, which is primarily regulated by foot placement. Variability of foot placement has been associated with falls, but these associations are inconsistent and generally for smooth, level flooring. This study investigates the control of foot placement and the associated gait variability in younger and older men and women (N=7/group, total N=28) while walking at three different speeds (slow, preferred, and fast) across a control surface with no obstacles and surfaces with multiple (64) small (10cm long ×13mm high) visible and hidden obstacles. Minimum obstacle distance between the shoe and nearest obstacle during each footfall was greater on the visible obstacles surface for older subjects because some of them chose to actively avoid obstacles. This obstacle avoidance strategy was implemented primarily by modulating step width and to a lesser extent step length as indicated by linear regressions of step width and length variability on minimum obstacle distance. Mean gait speed, step length, step width, and step time did not significantly differ by subject group, flooring surface, or obstacle avoidance strategy. Some healthy older subjects choose to actively avoid small obstacles that do not substantially perturb their gait by modulating step width and, to a lesser extent, step length. It is not clear if this obstacle avoidance strategy is appropriate and beneficial or overcautious and maladaptive, as it results in fewer obstacles encountered at a consequence of a less efficient gait pattern that has been shown to indicate increased fall risk. Further research is needed on the appropriateness of strategy selection when the environmental demands and/or task requirements have multiple possible completion strategies with conflicting objectives (i.e. perceived safety vs. efficiency).Keywords
This publication has 18 references indexed in Scilit:
- Obstacle crossing deficits in older adults: A systematic reviewGait & Posture, 2009
- Walking speed-related changes in stride time variability: effects of decreased speedJournal of NeuroEngineering and Rehabilitation, 2009
- Too much or too little step width variability is associated with a fall history in older persons who walk at or near normal gait speedJournal of NeuroEngineering and Rehabilitation, 2005
- Variability of step kinematics in young and older adultsGait & Posture, 2004
- Step width variability, but not step length variability or step time variability, discriminates gait of healthy young and older adults during treadmill locomotionJournal of Biomechanics, 2004
- Strategies for dynamic stability during adaptive human locomotionIEEE Engineering in Medicine and Biology Magazine, 2003
- Gait variability and fall risk in community-living older adults: A 1-year prospective studyArchives of Physical Medicine and Rehabilitation, 2001
- Increased gait unsteadiness in community-dwelling elderly fallersArchives of Physical Medicine and Rehabilitation, 1997
- Gait Changes in Older Adults: Predictors of Falls or Indicators of Fear?Journal of the American Geriatrics Society, 1997
- An Epidemiologic Study of Fall‐Related Fractures Among Institutionalized Older PeopleJournal of the American Geriatrics Society, 1995